We present a theory of quantum-coherent transport through a lateral p-n-p structure in graphene, which fully accounts for the interference of forward and backward scattering on the p-n interfaces. The backreflection amplitude changes sign at zero incidence angle because of the Klein phenomenon, adding a phase π to the interference fringes. The contributions of the two p-n interfaces to the phase of the interference cancel with each other at zero magnetic field, but become imbalanced at a finite field. The resulting half a period shift in the Fabry-Perot fringe pattern, induced by a relatively weak magnetic field, can provide a clear signature of Klein scattering in graphene. This effect is shown to be robust in the presence of spatially inhomogeneous potential of moderate strength.
@article{arxiv.0808.0488,
title = {Klein Backscattering and Fabry-Perot Interference in Graphene Heterojunctions},
author = {A. V. Shytov and M. S. Rudner and L. S. Levitov},
journal= {arXiv preprint arXiv:0808.0488},
year = {2008}
}